OS 10.4 - weird icon when booting up (folder with question mark)

Hi,
When i boot up I get a weird folder icon in the center of the screen, the folder will ahve a question mark on it? Does anyone know whats happening. After the folder icon shows up my apple icon comes up then I can login without any problems. Seems like I got some errors needing debugging going on.

When you see that icon, it means the system can't readily find a valid OS. It could be because somehow your settings tell it to look for it on a network (I've seen some app installs do this) or, if all the setting in the System Prefs seem correct, it could be because your system needs some cleaning up.

If it does need cleaning up, download MainMenu, if you don't already have it, and run all the cleaning tasks and also the rebuilding tasks (you'll need to restart of course). That might fix it.

If you have DiskWarrior I would also run that: it will repair the directory and is a must-have utility for me.